/*
 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * questions.
 */
package com.oracle.max.graal.compiler.tests;

import static com.oracle.max.graal.graph.iterators.NodePredicates.*;

import org.junit.Test;

import com.oracle.max.graal.compiler.phases.*;
import com.oracle.max.graal.debug.*;
import com.oracle.max.graal.graph.*;
import com.oracle.max.graal.nodes.*;

/**
 * In the following tests, the usages of local variable "a" are replaced with the integer constant 0.
 * Then canonicalization is applied and it is verified that the resulting graph is equal to the
 * graph of the method that just has a "return 1" statement in it.
 */
public class DegeneratedLoopsTest extends GraphTest {

    private static final String REFERENCE_SNIPPET = "referenceSnippet";

    @SuppressWarnings("all")
    public static int referenceSnippet(int a) {
        return 1;
    }

    @Test
    public void test1() {
        test("test1Snippet");
    }

    private static class UnresolvedException extends RuntimeException {
        private static final long serialVersionUID = 5215434338750728440L;

        static {
            if (true) {
                throw new UnsupportedOperationException("this class may never be initialized");
            }
        }
    }

    @SuppressWarnings("all")
    public static int test1Snippet(int a) {
        for (;;) {
            try {
                test();
                break;
            } catch (UnresolvedException e) {
            }
        }
        return a;
    }

    private static void test() {

    }

    private void test(String snippet) {
        StructuredGraph graph = parse(snippet);
        Debug.dump(graph, "Graph");
        LocalNode local = graph.getNodes(LocalNode.class).iterator().next();
        ConstantNode constant = ConstantNode.forInt(0, graph);
        for (Node n : local.usages().filter(isNotA(FrameState.class)).snapshot()) {
            n.replaceFirstInput(local, constant);
        }
        for (Invoke invoke : graph.getInvokes()) {
            invoke.intrinsify(null);
        }
        new CanonicalizerPhase(null, runtime(), null).apply(graph);
        StructuredGraph referenceGraph = parse(REFERENCE_SNIPPET); Debug.dump(referenceGraph, "Graph");
        assertEquals(referenceGraph, graph);
    }
}